Subdrain



Dec. 23, 1947. SHAFER. 2,433,300

SUBDRAIN Filed Feb. 25, 1946 INVENTOR. Gav/ a: .E. SHAFE ATTORNEYS.

Patented Dec. 23, 1947 UNITED STATES PATENT" OFFICE SUBDRAIN George E. Shafer, Middletown, Ohio, assignor to The American Rolling Mill Company, Middletown, Ohio, a corporation of Ohio Application February 23, 1946, Serial No. 649,506 10 Claims. (01. 61--11) This invention relates to a subdrain and more particularly to a subdrain made from sheet metal. In the past sheet metal subdrains have not been used to the maximum extent because they could not be manufactured at a low enough cost to compete with clay tile.

It is, therefore, an object of the present invention to provide a simple sheet metal subdrain which is susceptible of manufacture at a price which will put it in competition with clay tile. It is another object of my invention to provide a subdrain in which the principal strength against collapse is in one half the periphery, preferably the upper half.

It is another object of my invention to so design the other half that it will hold its principal shape and yet deflect and cooperate with the opposite half. It is another object of my invention to provide for stilfening of the lower half without offering substantial resistance to the flow of water through the drain and yet to provide for sufficient eddy currents to keep the drain clean.

Another object of my invention is to provide a subdrain which does not need to be perforated and yet which will allow water to enter in such a way that solids would have to move against gravity to enter the drain.

Further objects of my invention include the provision of a subdrain in which the sections will be completely nestable so that shipping space is economized, and which can be quickly and easily assembled with only a pair of common pliers.

These and other objects of my invention which will be described in more detail hereinafter or which will be apparent to one skilled in the art upon reading these specification I accomplish by that construction and arrangement of parts of which I shall now describe exemplary embodiments.

Reference is made to the drawings forming a part hereof and in which Figure 1 is an end elevation view of one embodiment of my invention.

Figure 2 is a plan view of the same as seen from above.

Figure 3 is a side elevational view of the same.

Figure 4 is a partial bottom view of the same.

Figure 5 is a partial detailed cross-sectional View on an enlarged scale taken on the line 5, 5 of Figure 2.

Figure 6 is a partial elevational view of a modification of my invention, and Figure 7 is a partial cross-sectional view of the same on the line 1-1 of Figure 6.

Briefly in the practice of my invention I make my subdrain in two halves; an upper half indicated generally at I U and a lower half indicated generally at H. The upper half will preferably be corrugated transversely in order to give it arch strength against crushing while the lower half will preferably be designed for favorable flow characteristics. The joint between the upper and lower halves is such as to provide for bracing of the weaker (lower) half by the stronger (upper) half, and to provide a desirable type of waterway opening into the subdrain without requiring perforation of the pipe.

In the embodiment of Figs. 1-5 inclusive, the upper half will have the longitudinal edges bent upwardly and then again downwardly in a reverse curve as indicated at l2. The lower half will not be corrugated. in theconvent'ional sense of the word, but will have angular ribs 14 formed therein for the purpose of strengthening the lower half of thedrain and also for the purpose of providing for a certain amount of eddy currents in order to keep the conduit clean. As will be clear from a consideration of Figures 1 and 4 the members M are preferably tapered as to width and depth so that there will be a minimum of interference with flow since the bottom of the drain will b substantially smooth as indicated at I3. The longi tudinal edges of the lower half of section II will be bent outwardly in a reverse curve as indicated at IS. The curvature l5 and the curvature l2,will be the same so that the upper section IU of the drain rests upon the lower section of the drain with the members l2 of the upper section fitting over the members 15 of the lower section.

If it is felt desirable to secure the two halves together, it is only necessary to bend lips l2a inwardly to engage under the members I 5 as shown in Figure 5. This can easily be done with a pair of pliers.

By reference to Figures 4 and 5, it will be observed that a series of openings "5 are formed between the upper side of the member I5 and the lower side of the member l2 by virtue of the fact that the member I5 is smooth and the member [2 is corrugated. By particular reference to Figure 5 it will be clear that the openings 16 form inverted U-shaped passages communicating with the interior of the drain, so that water can enter the drain as indicated by the arrow I! in Figure 5. The broken line I8 illustrates the water table and it will be clear that solid matter would have to go against the force of gravity to enter into the drain while water will enter as long as the Water table is as indicated at l8 or higher.

In order to stagger the circumferential seams it may be desirable to provide, for any given 3 length of subdrain, one upper member and one lower member which are shorter than the standard length. The short upper member may be used at one end and the short lower member at the other end, whereby no circumferential seam will be continuous around the pipe.

From the foregoing description it will be clear that this subaram is very simple to install because it is only necessary to lay the upper half on top of the lower half and, if desired, crimp in a series of lips [2a and to lay the assembled drain in a ditch which can then be filled in. It will alse be clear that by virtue of the construction of the lower half of the drain, there is very little interference with the fiow of water while at the same time this section has strengthening means giving it a good beam strength. It will also be clear that the upper section by virtue of its form, has great crushing strength and that by virtue of the connection between the two sections an entry way is provided fer water while solid matter is not permitted to enter.

In Figs. 6 and '7 l'. have illustrated a still more inexpensive embodiment of my invention, em'- bodying the same fundamental principles set forth above. The upper half is designated Illa and the lower half lld, and as willbe clear from the figures, these sections are structurally like those of Figures 1 to inclusive. However, I employ a modified joint structure which is considerably cheaper. I strike out a series of lips l5a, preferably along the edges of the lower half section, and assemble the conduit by simply fitting the edges of the upper half section between the edges of the lower half section and the lips l5a. In this way there are provided at lfia a series of waterway openings into the subdrain structure, so that a separate perforating operation is unnecessary.

It will be clear that numerous modifications may be made without departing from the spirit of my invention and I, therefore, do not intend to limit myself except as pointed out in the claims as follows. Having now fully described my invention, what I claim as new and desire to secure by Letters Patent is: u g V V 1. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper half sections being formed primarily for strength characteristics, said lower half sections being formed primarily for flow characteristics, but having strengthening configurations starting near the center line thereof and becoming inereasingly pronounced toward the longitudinal edges thereof, and longitudinal joints between said upper and lower half sections, said joints providing waterway openings into said drain structure.

2. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper half sections being transversely corrugated in order to give said half sections arch strength characteristics, said lower half sections having strengthening grooves extending from substantially the edges thereof to near the center line leaving a substantially smooth bottom for better flow characteristics, and longitudinal joints between said sections providing waterway openings into said drain structure.

3. A sheet metal drain structure comprising upper and lower arcuatehalf sections, both of said sections having their longitudinal edges bent upwardly, outwardly and downwardly to form inverted U shape'd members mating together, one of said inverted U-shaped members being corrugated and the other being free of corrugations,

4 whereby there are formed between said U-shaped members a series of inverted U-shaped passageways.

4. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper section having peripheral corrugations and having its longitudinal edges bent back upon themselves and then outwardly and downwardly to form inverted U-shaped members, said lower section having its longitudinal edges bent over outwardly and downwardly to form inverted U- shaped members mating with said first-mentioned U-shaped members, said second-mentioned U- shaped members being free of corrugations whereby there are formed between said U-shaped members a series of inverted U-shaped passageways.

5. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper section having peripheral corrugations and having its longitudinal edges bent back upon themselves and then outwardly and downwardly to form inverted U-shaped members, said lower section having its longitudinal edges bent over outwardly and downwardly to form inverted U- shaped members mating with said first-mentioned U-shaped members, said second-mentioned U- shaped members being free of corrugations whereby there are formed between said U-shaped members a series of inverted U-shaped passageways, and lips bent inwardly from the edges of said first-mentioned Ushaped members and engaging under the edges of said second-mentioned U-shaped members.

6. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper section having peripheral corrugations and having its longitudinal edges bent back upon themselves and then outwardly and downwardly to form inverted U-shaped members, said lower section having tapered angularly disposed grooves extending from near the edges to near the center line of said section leaving a central portion thereof substantially smooth, said lower section having its longitudinal edges bent over outwardly and downwardly to form inverted U-shaped members mating with said first-mentioned U- shaped members, and lips bent inwardly from the edges of said first-mentioned U-shaped members and engaging under the edges of said secondmentioned U-shaped members.

I. A sneet metal drain structure comprising upper and lower arcuate half sections, said upper section having peripheral corrugations and having its longitudinal edges bent back upon themselves and then outwardly and downwardly to form inverted U-shaped members, said lower section having angularly disposed grooves extend= ing from near the edges to near the center line of said section leaving a central portion thereof substantially smooth, said lower section having its longitudinal edges bent over outwardly and downwardly to form inverted U-shaped members mating with said first-mentioned U shaped members, and lips bent inwardly from the edges of said first-mentioned U-shaped members and engaging under the edges of said second-mam tioned U-shaped members.

8. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper section having peripheral corrugations and hav ing its longitudinal edges bent back upon themselves and then outwardly and downwardly to form inverted U=shaped members, said lower section having angularly disposed grooves extending from near the edges to near the center line of said section, said grooves being narrower and shallower adjacent said center line whereby the center portion of said section is substantially smooth, said lower section having its longitudinal edges bent over outwardly and downwardly to form inverted U-shaped members mating with said first-mentioned bent inwardly from the edges of said first-mentioned U-shaped members and engaging under the edges of said second-mentioned U-shaped members.

9. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper half sections being transversely corrugated in order to give said half sections arch strength characteristics, said lower half sections having strengthening grooves extending from substantially the edges thereof to near the center line leaving a substantially smooth bottom for better fiow characteristics, a series of lips struck out from the edges of one of said half sections, the edges of the other of said half sections seated between the edges of said one of said half sections and said lips, said joints forming Waterway openings into said drain structure.

U-shaped members, and lips 10. A sheet metal drain structure comprising upper and lower arcuate half sections, said upper half sections being transversely corrugated in order to give said half sections arch strength characteristics, said lower half sections having strengthening grooves extending from substantially the edges thereof to near the center line leaving a substantially smooth bottom for better flow characteristics, a series of lips struck out from the edges of said lower half sections, the edges of said upper half sections seated between the edges of said lower half sections and said lips, said joints forming waterway openings into said drain structure.

GEORGE E. SHAFER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

